GNU C++ STL

Выдержка из технического описания GNU C++ STL (libstdc++):

" CString suffers from a common programming error that results in
poor performance. Consider the following code:

CString n_copies_of (const CString& foo, unsigned n)
{
CString tmp;
for (unsigned i = 0; i < n; i++)
tmp += foo;
return tmp;
}

This function is O(n^2), not O(n). The reason is that each +=
causes a reallocation and copy of the existing string. Microsoft
applications are full of this kind of thing (quadratic performance
on tasks that can be done in linear time) -- on the other hand,
we should be thankful, as it's created such a big market for high-end
ix86 hardware. :-)

If you replace CString with string in the above function, the
performance is O(n)."

Это должно быть смешно для тех, кто поймет, о чем идет речь :)